Why are people born with all their eggs, but not all their sperm?

[ccars1]

Hi there! I'm TAing for a human sexuality course, and one of the students asked why we're born with all our eggs, but sperm is produced as long as we're alive. Can anyone answer this, or link me to a resource that can? Everything I've looked at so far has explained the process itself, but nothing has explained WHY it is the way it is. Is there a generally accepted theory on this?

Thanks!

[Jacob]

Ok so I don't *know* know. And sometimes biology doesn't have a 'reason' so much as a cause, or sometimes a quirk that isn't swept away by evolution simply because it isn't disadvantageous enough.

But the two things that come to mind:

1. A lot more sperm is produced... like millions of sperms per egg... So you're going to want to produce them at a bit more of an industrial scale. The mechanics of reproduction as they are sorta need it to be that way.

Human Reproduction: A Seafarer's Guide

2. Testosterone kicks in a lot later during foetal development so perhaps that has an influence on how the testes develop.

Maybe the biology teacher you are working with has a bit more insight too!